Irreversible electroporation (IRE) is a powerful new ablation technology that overcomes many of the primary limitations of thermal ablation approaches. However, for accurate, early prediction of treatment response, follow-up imaging methods must permit in vivo discrimination of irreversibly electroporated tissues from adjacent inadequately treated, reversibly electroporated tissues. Our most recent studies have demonstrated that quantitative MRI methods can detect electroporation-induced alterations to the cell membrane in both tumor and normal tissues. We will develop a powerful new MRI-guided IRE approach permitting a) pre- procedural planning to predict IRE ablation volumes, b) intra-procedural monitoring of tissue response and c) early post-procedural identification of inadequately treated (reversibly electroporated) tissues. Our ultimate goal is to achieve complete treatment of targeted tumors while avoiding excessive damage to adjacent liver tissues. The proposed pre-clinical project will address the following Specific Aims in a well-established rabbit liver tumor model: Specific Aim 1: To develop pre-procedural planning techniques to more accurately predict IRE ablation volumes. Specific Aim 2: To develop intra-procedural imaging methods for immediate functional monitoring of tumor tissue response. Specific Aim 3: To develop post-procedural imaging methods for early identification of inadequately treated, reversibly electroporated tumor tissues.